An ultra-sensitive kaempferol electrochemical sensor based on flower-like ZIF-8 pyrolysis-derived ZnWO4/porous nanocarbon composites

Kaempferol (KA), an important polyphenolic compound, is able to combat a variety of inflammatory diseases. Here, a ZnWO4 / porous nanocarbon based electrochemical sensor has been constructed to detect KA for the first time. Innovatively, ZnWO4 has been synthesized by pyrolysis using ZIF-8 as a zinc source, while porous nanocarbon was introduced. The nanocomposites have been characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy and demonstrated that Acidified ZnWO4/porous nanocarbon has been successfully prepared. Notably, the excellent catalytic properties of ZnWO4 and the great enrichment ability and conductivity of porous nanocarbon greatly enhanced the detection performance of the sensor for KA with a linear range of 0.009–0.7 μM and a LOD of 2.03 nM. In addition, the sensor has obtained satisfactory results for the detection of KA in actual natural samples (broccoli and kaempferia powder). The reaction sites and redox mechanism of KA were shown by density functional theory. Finally, the sensor is highly sensitive and stable, making it a novel detection method with extremely high potential applications.